Most actors fight being pigeonholed. Sylvester Stallone punched his way into being typecast and isn’t rushing to abandon his perch.

In the past 37 years, he’s portrayed, among other macho muscle-bound characters, boxer Rocky Balboa six times (with another opportunity reportedly on the way), and what does he do in the meantime? He stars in “Grudge Match” as Henry “Razor” Sharp, a former light heavyweight champ. Razor inexplicably fled the sport in his heyday, avoiding a tie-breaking fight with longtime rival Billy “The Kid” McDonnen (played by Robert De Niro, also a boxer portrayer, but with a decidedly more diverse résumé).

Sly’s still got it — when it comes to action. Razor is lured out of retirement for the bout he evaded three decades earlier, and all the requisite training scenes — the jabbing and jogging, raw-egg-swilling and truck-pulling — are nearly as exhilarating as they were in 1976. All these years later, the 67-year-old Stallone still looks the part with his tattooed barrel chest and ability to believably land a punch.

Stallone’s acting, however, is a little rusty. With his garbled delivery, he never was a paragon of emotional depth, but now his frozen face only exacerbates his shortcomings when the comedic drama turns serious. Even the more lighthearted scenes can be problematic. When Razor and the Kid are supposed to be publicly promoting their bout and instead devolve into bickering buffoonery, there’s nothing but ill-timed punch lines where the chemistry between Stallone and De Niro should be.

Luckily, a strong supporting cast makes up for the protagonists’ tepid interactions. The brilliant duo of Kevin Hart and Alan Arkin steal the show as the fight organizer and Razor’s dirty-old-man trainer, respectively. When these two get into it, laugh-out-loud hysterics follow. Meanwhile, Jon Bernthal (from AMC’s “The Walking Dead”) steps up to remind viewers how dramatic acting should look, playing the Kid’s estranged son.

The Kid isn’t much of a father, nor is he a particularly good person, although there are momentary flashes of his humanity. He’s a mostly two-dimensional character, and Stallone might have been better cast in the role.

As it is, Razor is the more likable of the two, but there’s an inverse correlation between each scene’s potential for enjoyment and the number of lines Stallone has to say. For example, nearly wordless sight gags involving the pair fighting while wearing green unitards and a skydiving ad­ven­ture gone awry garner laughs. Less effective is a romantic subplot between Razor and a former girlfriend played by Kim Basinger.

While this season has featured a wealth of great dramatic movies, everyone needs a break from the seriousness now and then. “Grudge Match” serves that function. It has its flaws, with a star who does the sometimes-silly script few favors. But you have to hand it to Stallone and his enduring career. It’s amazing that he’s still kicking, not to mention punching.

Stephanie Merry writes stories about pop culture for the Style section and reviews movies for Weekend. She joined The Washington Post in June 2008 after working on the business side at the Hill newspaper.